1. Field of the Invention
This invention relates to a method of operating a hydro-cyclone and to a hydro-cyclone.
2. Summary of the Invention
In accordance with the invention, there is provided a method of operating a hydro-cyclone comprising
a hollow, round casing having, co-axially in series, a cylindrical portion and a frusto-conical portion, the frusto-conical portion tapering toward one end of the hydro-cyclone; PA1 an end plate closing an axially outer end of the cylindrical portion opposed to said one end; PA1 a tangential inlet into the cylindrical portion; PA1 a co-axial, light fraction outlet through said end plate; and PA1 a co-axial, heavy fraction outlet at said one, taper end of the frusto-conical portion, the method including the step of drawing-off fluid flowing from the inlet inwardly adjacent the end plate. PA1 a hollow, round casing having, co-axially in series, a cylindrical portion and a frusto-conical portion, the frusto-conical portion tapering toward one end of the hydro-cyclone; PA1 an end plate closing an outer end of the cylindrical portion opposed to said one end; PA1 a tangential inlet into the cylindrical portion; PA1 a co-axial, light fraction outlet through said end plate; PA1 a co-axial, heavy fraction outlet at said one, taper end of the frusto-conical portion; and PA1 a circulation outlet in the end plate arranged to draw-off fluid flowing in use from the inlet inwardly adjacent the end plate.
Such drawing-off may preferably take place annularly outwardly of the light fraction outlet. Preferably, the light fraction outlet will be provided at a position axially spaced from the end plate.
The method may include circulating the drawn-off fluid by conducting it to a feed stream upstream of the inlet. Instead, the method may include conducting the drawn-off fluid to an underflow downstream of the heavy fraction outlet.
The invention extends to a hydro-cyclone comprising
Preferably, the circulation outlet is arranged annularly outwardly of the light fraction outlet. The circulation outlet may be substantially at the level of or in the plane of the end plate, the light fraction outlet being provided by a porthole in the cylindrical portion axially spaced from the end plate.
The circulation outlet may be in communication with a plenum downstream thereof. The plenum may be connected to a feed passage upstream of the tangential inlet. Instead, the plenum may be connected to an underflow passage downstream of the heavy fraction outlet.